1. Field of the Invention
The present invention relates to a movement compensation and control apparatus incorporated within a camera, which prevents a trembling of a picture due to unintentional movement such as camera shake.
2. Description of the Related Art
In a conventional trembling compensation and control apparatus, an angular displacement of an optical axis is detected by a vibration gyro or other angular velocity sensors, and an angular displacement velocity signal output from the angular velocity sensor is input to a low-cut filter which eliminates the low frequency component including direct current (DC) offset component. The angular displacement velocity signal is integrated, in an integration calculation portion, so as to be converted into an angular displacement signal. A compensation optical system is controlled in response to the angular displacement signal such that the movement is canceled, and a photograph is prevented from trembling. However, the conventional apparatus is ineffective for large movements, as in cases of panning and tilting.
Although the low-cut filter gradually eliminates the DC component, the angular displacement velocity signal output from the angular velocity sensor includes a much larger DC component during panning and tilting, than that caused by usual camera shake. This excessively high DC component is input to the low-cut filter which eliminates the DC component at low speed. Therefore, the DC component cannot be completely canceled, and the remaining DC component is integrated. As a result, the angular displacement signal increases steeply. When the panning or the tilting is completed, the output of the low-cut filter is reversed and is integrated such that the angular displacement signal decreases steeply.
The movement compensation is unnecessary for panning and tilting as they are intentional movements, however the conventional trembling compensation apparatus strongly activates the compensation optical system, causing substantial picture movement compensation, which is uncomfortable for the photographer.